Psalms 68:4 - Matthew Poole's English Annotations on the Holy Bible

Extol him, by praising him; of which this verb is used, Proverbs 4:8. Or rather, raise up or prepare the way for him; for so this word is commonly used, as Isaiah 57:14, Isaiah 57:10, and elsewhere. And this doubtless they did for this solemnity of bringing the ark to Zion. Compare Isaiah 40:3. That rideth upon the heavens; which phrase is used below, Psalms 68:33, though in differing words. Or, that did ride in the desert, where the ark was carried, and God marched along with it in the cloudy pillar. Or, that now rideth as (which particle is frequently understood) in the desert, i.e. that is now carried from place to place as it was in the desert. The word here rendered heavens doth generally signify the desert or plain fields, as Numbers 33:48,50 Numbers 36:13 Joshua 5:10 2 Samuel 4:7 Isaiah 40:3, compared with Luke 3:4. By his name Jah; whereby he is known and distinguished from all false gods; for Jah is generally conceived to be an abbreviature of the name Jehovah, which the heathens pronounced Jao. Before him; before the ark, where he is present, as David himself is said, to dance before the Lord upon this occasion, 2 Samuel 6:14.